WaterSubject

Inorder to aid the design and operation of activated sludge systems, thesoftware based on dynamic models belonging to the Activated SludgeModels is frequently used ASIM, SYMOS. Activated Sludge Models ASM,ASM-ASMd, ASM proposed by the IWA formerly IAWPRC, then IAWQ taskgroup have shown to be a good compromise between the complexity of theactivated sludge processes and the prediction of biological wastewatertreatment under dynamic conditions .However, a successful application of such modelling requires theestimation of kinetic and stoichiometric parameters as well aswastewater and activated sludge characterisation.Wastewatercharacterisation can be performed with the help of physicochemical orbiological methods. Taking into account that the ASMs are in generalbiologically defined models, the biological methods have found widerapplication than physicochemical tests .Among biological methods, respirometry has turned into one of the mostcommonly used methods for the purpose of wastewater characterisation .Respirometry is also a dominating method for the determination ofkinetic and stoichiometric parameters. It is based on the measurementand interpretation of the transient oxygen uptake rate OUR ofactivated sludge. have shown that the estimation of most kinetic parameters and of thewastewater compositions is possible by measuring OUR in simple batchtests. Several studies have been dedicated to evaluate and verify thecorrectness of this methodology for model calibration .Finally, the methods based on batch respirometric experiments have beenrecommended by the authors of ASM and have become a standard tool forASM calibration, especially in terms of kinetic parametersâ?? estimation .Syntheticsurfactants are extensively used in households as well as in industrialprocesses. Most of the surfactants consumed nowadays are anionic ornonionic surfactants .Biodegradation and environmental impact of anionic and nonionicsurfactants have been the subject of substantial research for manyyears .So far, the quantitative description of the kinetics of syntheticsurfactantsâ?? microbiological decomposition has been presented only in afew studies .Themain aim of this work was to describe and discuss the kinetics of theaerobic heterotrophic biodegradation of organic matter in wastewatercontaining the most commonly used anionic and nonionic surfactants ofdifferent chemical structure at elevated concentration mg lâ??. Thus, the kinetic and stoichiometricparameters for such activated sludge processes were determined with thehelp of respirometric methods. Additionally, wastewater containingsynthetic surfactants was characterised in terms of the COD fractions.